Dillon Tart turned himself in at the magistrate's office in Lillington late Monday afternoon.
On June 4, Ashley Moore died after Tart's SUV slammed into the Wal-Mart store on U.S. 421 between Erwin and Dunn.
Tart was behind the wheel of his SUV when it roared through the Wal-Mart parking lot, hit two vehicles, flipped and then slammed into the store's fire exit doors and a portion of a brick wall.
He told ABC11 in an interview earlier this month that he is heartbroken and haunted by a tragedy, he says, he doesn't remember.
"Sometimes I do wish I could remember what happened, other times I don't want to remember at all," he said.
Tart's mother, Patricia Jackson, told ABC11 as she left the detention Monday that her son was visibly upset. Tart's lawyer says he too is shocked by the grand jury's decision.
"He didn't kill his girlfriend," Tart's lawyer Jessee Jones said. "They charged him with second degree murder; you know the old saying a grand jury can convict a ham sandwich. I just don't see how these facts got second degree murder."
Ashley Moore's parents have declined comment.
Eyewitnesses reported that the couple argued in the parking lot of a gas station near the Wal-Mart store before the SUV sped off.
But Tart's mother told ABC11 last week that rumors and talk of a sinister motive are untrue. She says Tart suffers from seizures and she believes he had one before the crash.
"I know it was a tragic accident," Jackson said in an interview July 14. "I know in my heart he would never hurt her."
Tart is currently being held under no bond. His first court appearance is scheduled for 9:30 a.m. Tuesday. Tart's attorney says he will argue for a reduced bond.